1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds #include <linux/module.h> 31da177e4SLinus Torvalds #include <linux/sched.h> 41da177e4SLinus Torvalds #include <linux/ctype.h> 51da177e4SLinus Torvalds #include <linux/fd.h> 61da177e4SLinus Torvalds #include <linux/tty.h> 71da177e4SLinus Torvalds #include <linux/suspend.h> 81da177e4SLinus Torvalds #include <linux/root_dev.h> 91da177e4SLinus Torvalds #include <linux/security.h> 101da177e4SLinus Torvalds #include <linux/delay.h> 11d53d9f16SAndrew Morton #include <linux/mount.h> 12d779249eSGreg Kroah-Hartman #include <linux/device.h> 1346595390SAdrian Bunk #include <linux/init.h> 14011e3fcdSAdrian Bunk #include <linux/fs.h> 1582c8253aSAdrian Bunk #include <linux/initrd.h> 1622a9d645SArjan van de Ven #include <linux/async.h> 175ad4e53bSAl Viro #include <linux/fs_struct.h> 185a0e3ad6STejun Heo #include <linux/slab.h> 1957f150a5SRob Landley #include <linux/ramfs.h> 2016203a7aSRob Landley #include <linux/shmem_fs.h> 211da177e4SLinus Torvalds 221da177e4SLinus Torvalds #include <linux/nfs_fs.h> 231da177e4SLinus Torvalds #include <linux/nfs_fs_sb.h> 241da177e4SLinus Torvalds #include <linux/nfs_mount.h> 254f5b246bSChristoph Hellwig #include <linux/raid/detect.h> 26e262e32dSDavid Howells #include <uapi/linux/mount.h> 271da177e4SLinus Torvalds 281da177e4SLinus Torvalds #include "do_mounts.h" 291da177e4SLinus Torvalds 309b04c997STheodore Ts'o int root_mountflags = MS_RDONLY | MS_SILENT; 31f56f6d30SAdrian Bunk static char * __initdata root_device_name; 321da177e4SLinus Torvalds static char __initdata saved_root_name[64]; 3379975f13SWill Drewry static int root_wait; 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds dev_t ROOT_DEV; 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds static int __init load_ramdisk(char *str) 381da177e4SLinus Torvalds { 39c8376994SChristoph Hellwig pr_warn("ignoring the deprecated load_ramdisk= option\n"); 401da177e4SLinus Torvalds return 1; 411da177e4SLinus Torvalds } 421da177e4SLinus Torvalds __setup("load_ramdisk=", load_ramdisk); 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds static int __init readonly(char *str) 451da177e4SLinus Torvalds { 461da177e4SLinus Torvalds if (*str) 471da177e4SLinus Torvalds return 0; 481da177e4SLinus Torvalds root_mountflags |= MS_RDONLY; 491da177e4SLinus Torvalds return 1; 501da177e4SLinus Torvalds } 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds static int __init readwrite(char *str) 531da177e4SLinus Torvalds { 541da177e4SLinus Torvalds if (*str) 551da177e4SLinus Torvalds return 0; 561da177e4SLinus Torvalds root_mountflags &= ~MS_RDONLY; 571da177e4SLinus Torvalds return 1; 581da177e4SLinus Torvalds } 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds __setup("ro", readonly); 611da177e4SLinus Torvalds __setup("rw", readwrite); 621da177e4SLinus Torvalds 636d0aed7aSJens Axboe #ifdef CONFIG_BLOCK 641ad7e899SStephen Warren struct uuidcmp { 651ad7e899SStephen Warren const char *uuid; 661ad7e899SStephen Warren int len; 671ad7e899SStephen Warren }; 681ad7e899SStephen Warren 69b5af921eSWill Drewry /** 70b5af921eSWill Drewry * match_dev_by_uuid - callback for finding a partition using its uuid 71b5af921eSWill Drewry * @dev: device passed in by the caller 721ad7e899SStephen Warren * @data: opaque pointer to the desired struct uuidcmp to match 73b5af921eSWill Drewry * 74b5af921eSWill Drewry * Returns 1 if the device matches, and 0 otherwise. 75b5af921eSWill Drewry */ 769f3b795aSMichał Mirosław static int match_dev_by_uuid(struct device *dev, const void *data) 77b5af921eSWill Drewry { 780d02129eSChristoph Hellwig struct block_device *bdev = dev_to_bdev(dev); 799f3b795aSMichał Mirosław const struct uuidcmp *cmp = data; 80b5af921eSWill Drewry 810d02129eSChristoph Hellwig if (!bdev->bd_meta_info || 820d02129eSChristoph Hellwig strncasecmp(cmp->uuid, bdev->bd_meta_info->uuid, cmp->len)) 83b5af921eSWill Drewry return 0; 84013b0e96SChristoph Hellwig return 1; 85b5af921eSWill Drewry } 86b5af921eSWill Drewry 87b5af921eSWill Drewry /** 88b5af921eSWill Drewry * devt_from_partuuid - looks up the dev_t of a partition by its UUID 89a68b3108Schishanmingshen * @uuid_str: char array containing ascii UUID 90b5af921eSWill Drewry * 91b5af921eSWill Drewry * The function will return the first partition which contains a matching 92b5af921eSWill Drewry * UUID value in its partition_meta_info struct. This does not search 93b5af921eSWill Drewry * by filesystem UUIDs. 94b5af921eSWill Drewry * 95a68b3108Schishanmingshen * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be 9679975f13SWill Drewry * extracted and used as an offset from the partition identified by the UUID. 9779975f13SWill Drewry * 98b5af921eSWill Drewry * Returns the matching dev_t on success or 0 on failure. 99b5af921eSWill Drewry */ 1001ad7e899SStephen Warren static dev_t devt_from_partuuid(const char *uuid_str) 101b5af921eSWill Drewry { 1021ad7e899SStephen Warren struct uuidcmp cmp; 103b5af921eSWill Drewry struct device *dev = NULL; 104e036bb8eSChristoph Hellwig dev_t devt = 0; 10579975f13SWill Drewry int offset = 0; 106283f8fc0SStephen Warren char *slash; 10779975f13SWill Drewry 1081ad7e899SStephen Warren cmp.uuid = uuid_str; 1091ad7e899SStephen Warren 110283f8fc0SStephen Warren slash = strchr(uuid_str, '/'); 11179975f13SWill Drewry /* Check for optional partition number offset attributes. */ 112283f8fc0SStephen Warren if (slash) { 11379975f13SWill Drewry char c = 0; 114e036bb8eSChristoph Hellwig 11579975f13SWill Drewry /* Explicitly fail on poor PARTUUID syntax. */ 116e036bb8eSChristoph Hellwig if (sscanf(slash + 1, "PARTNROFF=%d%c", &offset, &c) != 1) 117e036bb8eSChristoph Hellwig goto clear_root_wait; 118283f8fc0SStephen Warren cmp.len = slash - uuid_str; 119283f8fc0SStephen Warren } else { 120283f8fc0SStephen Warren cmp.len = strlen(uuid_str); 121283f8fc0SStephen Warren } 122283f8fc0SStephen Warren 123e036bb8eSChristoph Hellwig if (!cmp.len) 124e036bb8eSChristoph Hellwig goto clear_root_wait; 125b5af921eSWill Drewry 126e036bb8eSChristoph Hellwig dev = class_find_device(&block_class, NULL, &cmp, &match_dev_by_uuid); 127b5af921eSWill Drewry if (!dev) 128e036bb8eSChristoph Hellwig return 0; 129b5af921eSWill Drewry 130e036bb8eSChristoph Hellwig if (offset) { 131e036bb8eSChristoph Hellwig /* 132e036bb8eSChristoph Hellwig * Attempt to find the requested partition by adding an offset 133e036bb8eSChristoph Hellwig * to the partition number found by UUID. 134e036bb8eSChristoph Hellwig */ 135c97d93c3SChristoph Hellwig devt = part_devt(dev_to_disk(dev), 1360d02129eSChristoph Hellwig dev_to_bdev(dev)->bd_partno + offset); 137e036bb8eSChristoph Hellwig } else { 138e036bb8eSChristoph Hellwig devt = dev->devt; 139e036bb8eSChristoph Hellwig } 14079975f13SWill Drewry 14179975f13SWill Drewry put_device(dev); 142e036bb8eSChristoph Hellwig return devt; 143e036bb8eSChristoph Hellwig 144e036bb8eSChristoph Hellwig clear_root_wait: 145283f8fc0SStephen Warren pr_err("VFS: PARTUUID= is invalid.\n" 146283f8fc0SStephen Warren "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); 147283f8fc0SStephen Warren if (root_wait) 148283f8fc0SStephen Warren pr_err("Disabling rootwait; root= is invalid.\n"); 149283f8fc0SStephen Warren root_wait = 0; 150e036bb8eSChristoph Hellwig return 0; 151b5af921eSWill Drewry } 152f027c34dSNikolaus Voss 153f027c34dSNikolaus Voss /** 154f027c34dSNikolaus Voss * match_dev_by_label - callback for finding a partition using its label 155f027c34dSNikolaus Voss * @dev: device passed in by the caller 156f027c34dSNikolaus Voss * @data: opaque pointer to the label to match 157f027c34dSNikolaus Voss * 158f027c34dSNikolaus Voss * Returns 1 if the device matches, and 0 otherwise. 159f027c34dSNikolaus Voss */ 160f027c34dSNikolaus Voss static int match_dev_by_label(struct device *dev, const void *data) 161f027c34dSNikolaus Voss { 1620d02129eSChristoph Hellwig struct block_device *bdev = dev_to_bdev(dev); 163f027c34dSNikolaus Voss const char *label = data; 164f027c34dSNikolaus Voss 1650d02129eSChristoph Hellwig if (!bdev->bd_meta_info || strcmp(label, bdev->bd_meta_info->volname)) 166f027c34dSNikolaus Voss return 0; 167013b0e96SChristoph Hellwig return 1; 168f027c34dSNikolaus Voss } 169c2637e80SChristoph Hellwig 170c2637e80SChristoph Hellwig static dev_t devt_from_partlabel(const char *label) 171c2637e80SChristoph Hellwig { 172c2637e80SChristoph Hellwig struct device *dev; 173c2637e80SChristoph Hellwig dev_t devt = 0; 174c2637e80SChristoph Hellwig 175c2637e80SChristoph Hellwig dev = class_find_device(&block_class, NULL, label, &match_dev_by_label); 176c2637e80SChristoph Hellwig if (dev) { 177c2637e80SChristoph Hellwig devt = dev->devt; 178c2637e80SChristoph Hellwig put_device(dev); 179c2637e80SChristoph Hellwig } 180c2637e80SChristoph Hellwig 181c2637e80SChristoph Hellwig return devt; 182c2637e80SChristoph Hellwig } 183c2637e80SChristoph Hellwig 184c2637e80SChristoph Hellwig static dev_t devt_from_devname(const char *name) 185c2637e80SChristoph Hellwig { 186c2637e80SChristoph Hellwig dev_t devt = 0; 187c2637e80SChristoph Hellwig int part; 188c2637e80SChristoph Hellwig char s[32]; 189c2637e80SChristoph Hellwig char *p; 190c2637e80SChristoph Hellwig 191c2637e80SChristoph Hellwig if (strlen(name) > 31) 192c2637e80SChristoph Hellwig return 0; 193c2637e80SChristoph Hellwig strcpy(s, name); 194c2637e80SChristoph Hellwig for (p = s; *p; p++) { 195c2637e80SChristoph Hellwig if (*p == '/') 196c2637e80SChristoph Hellwig *p = '!'; 197c2637e80SChristoph Hellwig } 198c2637e80SChristoph Hellwig 199c2637e80SChristoph Hellwig devt = blk_lookup_devt(s, 0); 200c2637e80SChristoph Hellwig if (devt) 201c2637e80SChristoph Hellwig return devt; 202c2637e80SChristoph Hellwig 203c2637e80SChristoph Hellwig /* 204c2637e80SChristoph Hellwig * Try non-existent, but valid partition, which may only exist after 205c2637e80SChristoph Hellwig * opening the device, like partitioned md devices. 206c2637e80SChristoph Hellwig */ 207c2637e80SChristoph Hellwig while (p > s && isdigit(p[-1])) 208c2637e80SChristoph Hellwig p--; 209c2637e80SChristoph Hellwig if (p == s || !*p || *p == '0') 210c2637e80SChristoph Hellwig return 0; 211c2637e80SChristoph Hellwig 212c2637e80SChristoph Hellwig /* try disk name without <part number> */ 213c2637e80SChristoph Hellwig part = simple_strtoul(p, NULL, 10); 214c2637e80SChristoph Hellwig *p = '\0'; 215c2637e80SChristoph Hellwig devt = blk_lookup_devt(s, part); 216c2637e80SChristoph Hellwig if (devt) 217c2637e80SChristoph Hellwig return devt; 218c2637e80SChristoph Hellwig 219c2637e80SChristoph Hellwig /* try disk name without p<part number> */ 220c2637e80SChristoph Hellwig if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') 221c2637e80SChristoph Hellwig return 0; 222c2637e80SChristoph Hellwig p[-1] = '\0'; 223c2637e80SChristoph Hellwig return blk_lookup_devt(s, part); 224c2637e80SChristoph Hellwig } 225c2637e80SChristoph Hellwig #endif /* CONFIG_BLOCK */ 226c2637e80SChristoph Hellwig 227c2637e80SChristoph Hellwig static dev_t devt_from_devnum(const char *name) 228c2637e80SChristoph Hellwig { 229c2637e80SChristoph Hellwig unsigned maj, min, offset; 230c2637e80SChristoph Hellwig dev_t devt = 0; 231c2637e80SChristoph Hellwig char *p, dummy; 232c2637e80SChristoph Hellwig 233c2637e80SChristoph Hellwig if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 || 234c2637e80SChristoph Hellwig sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3) { 235c2637e80SChristoph Hellwig devt = MKDEV(maj, min); 236c2637e80SChristoph Hellwig if (maj != MAJOR(devt) || min != MINOR(devt)) 237c2637e80SChristoph Hellwig return 0; 238c2637e80SChristoph Hellwig } else { 239c2637e80SChristoph Hellwig devt = new_decode_dev(simple_strtoul(name, &p, 16)); 240c2637e80SChristoph Hellwig if (*p) 241c2637e80SChristoph Hellwig return 0; 242c2637e80SChristoph Hellwig } 243c2637e80SChristoph Hellwig 244c2637e80SChristoph Hellwig return devt; 245c2637e80SChristoph Hellwig } 246b5af921eSWill Drewry 2471da177e4SLinus Torvalds /* 2481da177e4SLinus Torvalds * Convert a name into device number. We accept the following variants: 2491da177e4SLinus Torvalds * 2500bf37ae4SPavel Machek * 1) <hex_major><hex_minor> device number in hexadecimal represents itself 2510bf37ae4SPavel Machek * no leading 0x, for example b302. 2521da177e4SLinus Torvalds * 2) /dev/nfs represents Root_NFS (0xff) 2531da177e4SLinus Torvalds * 3) /dev/<disk_name> represents the device number of disk 2541da177e4SLinus Torvalds * 4) /dev/<disk_name><decimal> represents the device number 2551da177e4SLinus Torvalds * of partition - device number of disk plus the partition number 2561da177e4SLinus Torvalds * 5) /dev/<disk_name>p<decimal> - same as the above, that form is 2571da177e4SLinus Torvalds * used when disk name of partitioned disk ends on a digit. 258b5af921eSWill Drewry * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 259b5af921eSWill Drewry * unique id of a partition if the partition table provides it. 260d33b98fcSStephen Warren * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS 261d33b98fcSStephen Warren * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- 262d33b98fcSStephen Warren * filled hex representation of the 32-bit "NT disk signature", and PP 263d33b98fcSStephen Warren * is a zero-filled hex representation of the 1-based partition number. 26479975f13SWill Drewry * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to 26579975f13SWill Drewry * a partition with a known unique id. 2666c251611SSebastian Capella * 8) <major>:<minor> major and minor number of the device separated by 2676c251611SSebastian Capella * a colon. 268f027c34dSNikolaus Voss * 9) PARTLABEL=<name> with name being the GPT partition label. 269f027c34dSNikolaus Voss * MSDOS partitions do not support labels! 2708902dd52SPaulo Alcantara (SUSE) * 10) /dev/cifs represents Root_CIFS (0xfe) 2711da177e4SLinus Torvalds * 272edfaa7c3SKay Sievers * If name doesn't have fall into the categories above, we return (0,0). 273edfaa7c3SKay Sievers * block_class is used to check if something is a disk name. If the disk 274edfaa7c3SKay Sievers * name contains slashes, the device name has them replaced with 275edfaa7c3SKay Sievers * bangs. 2761da177e4SLinus Torvalds */ 277e6e20a7aSDan Ehrenberg dev_t name_to_dev_t(const char *name) 2781da177e4SLinus Torvalds { 279c2637e80SChristoph Hellwig if (strcmp(name, "/dev/nfs") == 0) 280c2637e80SChristoph Hellwig return Root_NFS; 281c2637e80SChristoph Hellwig if (strcmp(name, "/dev/cifs") == 0) 282c2637e80SChristoph Hellwig return Root_CIFS; 283c2637e80SChristoph Hellwig if (strcmp(name, "/dev/ram") == 0) 284c2637e80SChristoph Hellwig return Root_RAM0; 2856d0aed7aSJens Axboe #ifdef CONFIG_BLOCK 286c2637e80SChristoph Hellwig if (strncmp(name, "PARTUUID=", 9) == 0) 287c2637e80SChristoph Hellwig return devt_from_partuuid(name + 9); 288c2637e80SChristoph Hellwig if (strncmp(name, "PARTLABEL=", 10) == 0) 289c2637e80SChristoph Hellwig return devt_from_partlabel(name + 10); 290c2637e80SChristoph Hellwig if (strncmp(name, "/dev/", 5) == 0) 291c2637e80SChristoph Hellwig return devt_from_devname(name + 5); 2926d0aed7aSJens Axboe #endif 293c2637e80SChristoph Hellwig return devt_from_devnum(name); 2941da177e4SLinus Torvalds } 295e6e20a7aSDan Ehrenberg EXPORT_SYMBOL_GPL(name_to_dev_t); 2961da177e4SLinus Torvalds 2971da177e4SLinus Torvalds static int __init root_dev_setup(char *line) 2981da177e4SLinus Torvalds { 299a1d3a6d9SWolfram Sang strscpy(saved_root_name, line, sizeof(saved_root_name)); 3001da177e4SLinus Torvalds return 1; 3011da177e4SLinus Torvalds } 3021da177e4SLinus Torvalds 3031da177e4SLinus Torvalds __setup("root=", root_dev_setup); 3041da177e4SLinus Torvalds 305cc1ed754SPierre Ossman static int __init rootwait_setup(char *str) 306cc1ed754SPierre Ossman { 307cc1ed754SPierre Ossman if (*str) 308cc1ed754SPierre Ossman return 0; 309cc1ed754SPierre Ossman root_wait = 1; 310cc1ed754SPierre Ossman return 1; 311cc1ed754SPierre Ossman } 312cc1ed754SPierre Ossman 313cc1ed754SPierre Ossman __setup("rootwait", rootwait_setup); 314cc1ed754SPierre Ossman 3151da177e4SLinus Torvalds static char * __initdata root_mount_data; 3161da177e4SLinus Torvalds static int __init root_data_setup(char *str) 3171da177e4SLinus Torvalds { 3181da177e4SLinus Torvalds root_mount_data = str; 3191da177e4SLinus Torvalds return 1; 3201da177e4SLinus Torvalds } 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds static char * __initdata root_fs_names; 3231da177e4SLinus Torvalds static int __init fs_names_setup(char *str) 3241da177e4SLinus Torvalds { 3251da177e4SLinus Torvalds root_fs_names = str; 3261da177e4SLinus Torvalds return 1; 3271da177e4SLinus Torvalds } 3281da177e4SLinus Torvalds 3291da177e4SLinus Torvalds static unsigned int __initdata root_delay; 3301da177e4SLinus Torvalds static int __init root_delay_setup(char *str) 3311da177e4SLinus Torvalds { 3321da177e4SLinus Torvalds root_delay = simple_strtoul(str, NULL, 0); 3331da177e4SLinus Torvalds return 1; 3341da177e4SLinus Torvalds } 3351da177e4SLinus Torvalds 3361da177e4SLinus Torvalds __setup("rootflags=", root_data_setup); 3371da177e4SLinus Torvalds __setup("rootfstype=", fs_names_setup); 3381da177e4SLinus Torvalds __setup("rootdelay=", root_delay_setup); 3391da177e4SLinus Torvalds 340b51593c4SVivek Goyal /* This can return zero length strings. Caller should check */ 341b51593c4SVivek Goyal static int __init split_fs_names(char *page, size_t size, char *names) 3421da177e4SLinus Torvalds { 343b51593c4SVivek Goyal int count = 1; 3446e7c1770SChristoph Hellwig char *p = page; 3451da177e4SLinus Torvalds 346a1d3a6d9SWolfram Sang strscpy(p, root_fs_names, size); 3476e7c1770SChristoph Hellwig while (*p++) { 348b51593c4SVivek Goyal if (p[-1] == ',') { 3496e7c1770SChristoph Hellwig p[-1] = '\0'; 3506e7c1770SChristoph Hellwig count++; 351b51593c4SVivek Goyal } 352b51593c4SVivek Goyal } 3536e7c1770SChristoph Hellwig 3546e7c1770SChristoph Hellwig return count; 3551da177e4SLinus Torvalds } 3561da177e4SLinus Torvalds 357cccaa5e3SDominik Brodowski static int __init do_mount_root(const char *name, const char *fs, 358cccaa5e3SDominik Brodowski const int flags, const void *data) 3591da177e4SLinus Torvalds { 360d8c9584eSAl Viro struct super_block *s; 3617de7de7cSLinus Torvalds struct page *p = NULL; 3627de7de7cSLinus Torvalds char *data_page = NULL; 363cccaa5e3SDominik Brodowski int ret; 364cccaa5e3SDominik Brodowski 3657de7de7cSLinus Torvalds if (data) { 366c60166f0SChristoph Hellwig /* init_mount() requires a full page as fifth argument */ 367cccaa5e3SDominik Brodowski p = alloc_page(GFP_KERNEL); 368cccaa5e3SDominik Brodowski if (!p) 369cccaa5e3SDominik Brodowski return -ENOMEM; 370cccaa5e3SDominik Brodowski data_page = page_address(p); 371c60166f0SChristoph Hellwig /* zero-pad. init_mount() will make sure it's terminated */ 3727de7de7cSLinus Torvalds strncpy(data_page, data, PAGE_SIZE); 3737de7de7cSLinus Torvalds } 374cccaa5e3SDominik Brodowski 375c60166f0SChristoph Hellwig ret = init_mount(name, "/root", fs, flags, data_page); 376cccaa5e3SDominik Brodowski if (ret) 377cccaa5e3SDominik Brodowski goto out; 3781da177e4SLinus Torvalds 379db63f1e3SChristoph Hellwig init_chdir("/root"); 380d8c9584eSAl Viro s = current->fs->pwd.dentry->d_sb; 381d8c9584eSAl Viro ROOT_DEV = s->s_dev; 38280cdc6daSMandeep Singh Baines printk(KERN_INFO 38380cdc6daSMandeep Singh Baines "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", 384d8c9584eSAl Viro s->s_type->name, 385bc98a42cSDavid Howells sb_rdonly(s) ? " readonly" : "", 386d8c9584eSAl Viro MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 387cccaa5e3SDominik Brodowski 388cccaa5e3SDominik Brodowski out: 3897de7de7cSLinus Torvalds if (p) 390cccaa5e3SDominik Brodowski put_page(p); 391cccaa5e3SDominik Brodowski return ret; 3921da177e4SLinus Torvalds } 3931da177e4SLinus Torvalds 394e3102722SChristoph Hellwig void __init mount_root_generic(char *name, int flags) 3951da177e4SLinus Torvalds { 39675f296d9SLevin, Alexander (Sasha Levin) struct page *page = alloc_page(GFP_KERNEL); 397a608ca21SJeff Layton char *fs_names = page_address(page); 3981da177e4SLinus Torvalds char *p; 3991da177e4SLinus Torvalds char b[BDEVNAME_SIZE]; 4006e7c1770SChristoph Hellwig int num_fs, i; 4011da177e4SLinus Torvalds 402ea3edd4dSChristoph Hellwig scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)", 403ea3edd4dSChristoph Hellwig MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 404e24d12b7SChristoph Hellwig if (root_fs_names) 405b51593c4SVivek Goyal num_fs = split_fs_names(fs_names, PAGE_SIZE, root_fs_names); 406e24d12b7SChristoph Hellwig else 4076e7c1770SChristoph Hellwig num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE); 4081da177e4SLinus Torvalds retry: 4096e7c1770SChristoph Hellwig for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) { 410b51593c4SVivek Goyal int err; 411b51593c4SVivek Goyal 412b51593c4SVivek Goyal if (!*p) 413b51593c4SVivek Goyal continue; 414b51593c4SVivek Goyal err = do_mount_root(name, p, flags, root_mount_data); 4151da177e4SLinus Torvalds switch (err) { 4161da177e4SLinus Torvalds case 0: 4171da177e4SLinus Torvalds goto out; 4181da177e4SLinus Torvalds case -EACCES: 4191da177e4SLinus Torvalds case -EINVAL: 4201da177e4SLinus Torvalds continue; 4211da177e4SLinus Torvalds } 4221da177e4SLinus Torvalds /* 4231da177e4SLinus Torvalds * Allow the user to distinguish between failed sys_open 4241da177e4SLinus Torvalds * and bad superblock on root device. 425dd2a345fSDave Gilbert * and give them a list of the available devices 4261da177e4SLinus Torvalds */ 4270e0cb892SBernhard Walle printk("VFS: Cannot open root device \"%s\" or %s: error %d\n", 4280e0cb892SBernhard Walle root_device_name, b, err); 429dd2a345fSDave Gilbert printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); 4301da177e4SLinus Torvalds 431dd2a345fSDave Gilbert printk_all_partitions(); 4321da177e4SLinus Torvalds panic("VFS: Unable to mount root fs on %s", b); 4331da177e4SLinus Torvalds } 434e462ec50SDavid Howells if (!(flags & SB_RDONLY)) { 435e462ec50SDavid Howells flags |= SB_RDONLY; 43610975933SMiklos Szeredi goto retry; 43710975933SMiklos Szeredi } 438be6e028bSAndy Whitcroft 439dd2a345fSDave Gilbert printk("List of all partitions:\n"); 440dd2a345fSDave Gilbert printk_all_partitions(); 441be6e028bSAndy Whitcroft printk("No filesystem could mount root, tried: "); 4426e7c1770SChristoph Hellwig for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) 443be6e028bSAndy Whitcroft printk(" %s", p); 444be6e028bSAndy Whitcroft printk("\n"); 4459361401eSDavid Howells panic("VFS: Unable to mount root fs on %s", b); 4461da177e4SLinus Torvalds out: 447a608ca21SJeff Layton put_page(page); 4481da177e4SLinus Torvalds } 4491da177e4SLinus Torvalds 4501da177e4SLinus Torvalds #ifdef CONFIG_ROOT_NFS 45143717c7dSChuck Lever 45243717c7dSChuck Lever #define NFSROOT_TIMEOUT_MIN 5 45343717c7dSChuck Lever #define NFSROOT_TIMEOUT_MAX 30 45443717c7dSChuck Lever #define NFSROOT_RETRY_MAX 5 45543717c7dSChuck Lever 456*a6a41d39SChristoph Hellwig static void __init mount_nfs_root(void) 4571da177e4SLinus Torvalds { 45856463e50SChuck Lever char *root_dev, *root_data; 45943717c7dSChuck Lever unsigned int timeout; 460*a6a41d39SChristoph Hellwig int try; 4611da177e4SLinus Torvalds 462*a6a41d39SChristoph Hellwig if (nfs_root_data(&root_dev, &root_data)) 463*a6a41d39SChristoph Hellwig goto fail; 46443717c7dSChuck Lever 46543717c7dSChuck Lever /* 46643717c7dSChuck Lever * The server or network may not be ready, so try several 46743717c7dSChuck Lever * times. Stop after a few tries in case the client wants 46843717c7dSChuck Lever * to fall back to other boot methods. 46943717c7dSChuck Lever */ 47043717c7dSChuck Lever timeout = NFSROOT_TIMEOUT_MIN; 47143717c7dSChuck Lever for (try = 1; ; try++) { 472*a6a41d39SChristoph Hellwig if (!do_mount_root(root_dev, "nfs", root_mountflags, root_data)) 473*a6a41d39SChristoph Hellwig return; 47443717c7dSChuck Lever if (try > NFSROOT_RETRY_MAX) 47543717c7dSChuck Lever break; 47643717c7dSChuck Lever 47743717c7dSChuck Lever /* Wait, in case the server refused us immediately */ 47843717c7dSChuck Lever ssleep(timeout); 47943717c7dSChuck Lever timeout <<= 1; 48043717c7dSChuck Lever if (timeout > NFSROOT_TIMEOUT_MAX) 48143717c7dSChuck Lever timeout = NFSROOT_TIMEOUT_MAX; 48243717c7dSChuck Lever } 483*a6a41d39SChristoph Hellwig fail: 484*a6a41d39SChristoph Hellwig pr_err("VFS: Unable to mount root fs via NFS.\n"); 4851da177e4SLinus Torvalds } 486*a6a41d39SChristoph Hellwig #else 487*a6a41d39SChristoph Hellwig static inline void mount_nfs_root(void) 488*a6a41d39SChristoph Hellwig { 489*a6a41d39SChristoph Hellwig } 490*a6a41d39SChristoph Hellwig #endif /* CONFIG_ROOT_NFS */ 4911da177e4SLinus Torvalds 4928902dd52SPaulo Alcantara (SUSE) #ifdef CONFIG_CIFS_ROOT 4938902dd52SPaulo Alcantara (SUSE) 4948902dd52SPaulo Alcantara (SUSE) extern int cifs_root_data(char **dev, char **opts); 4958902dd52SPaulo Alcantara (SUSE) 4968902dd52SPaulo Alcantara (SUSE) #define CIFSROOT_TIMEOUT_MIN 5 4978902dd52SPaulo Alcantara (SUSE) #define CIFSROOT_TIMEOUT_MAX 30 4988902dd52SPaulo Alcantara (SUSE) #define CIFSROOT_RETRY_MAX 5 4998902dd52SPaulo Alcantara (SUSE) 500*a6a41d39SChristoph Hellwig static void __init mount_cifs_root(void) 5018902dd52SPaulo Alcantara (SUSE) { 5028902dd52SPaulo Alcantara (SUSE) char *root_dev, *root_data; 5038902dd52SPaulo Alcantara (SUSE) unsigned int timeout; 504*a6a41d39SChristoph Hellwig int try; 5058902dd52SPaulo Alcantara (SUSE) 506*a6a41d39SChristoph Hellwig if (cifs_root_data(&root_dev, &root_data)) 507*a6a41d39SChristoph Hellwig goto fail; 5088902dd52SPaulo Alcantara (SUSE) 5098902dd52SPaulo Alcantara (SUSE) timeout = CIFSROOT_TIMEOUT_MIN; 5108902dd52SPaulo Alcantara (SUSE) for (try = 1; ; try++) { 511*a6a41d39SChristoph Hellwig if (!do_mount_root(root_dev, "cifs", root_mountflags, 512*a6a41d39SChristoph Hellwig root_data)) 513*a6a41d39SChristoph Hellwig return; 5148902dd52SPaulo Alcantara (SUSE) if (try > CIFSROOT_RETRY_MAX) 5158902dd52SPaulo Alcantara (SUSE) break; 5168902dd52SPaulo Alcantara (SUSE) 5178902dd52SPaulo Alcantara (SUSE) ssleep(timeout); 5188902dd52SPaulo Alcantara (SUSE) timeout <<= 1; 5198902dd52SPaulo Alcantara (SUSE) if (timeout > CIFSROOT_TIMEOUT_MAX) 5208902dd52SPaulo Alcantara (SUSE) timeout = CIFSROOT_TIMEOUT_MAX; 5218902dd52SPaulo Alcantara (SUSE) } 522*a6a41d39SChristoph Hellwig fail: 523*a6a41d39SChristoph Hellwig pr_err("VFS: Unable to mount root fs via SMB.\n"); 5248902dd52SPaulo Alcantara (SUSE) } 525*a6a41d39SChristoph Hellwig #else 526*a6a41d39SChristoph Hellwig static inline void mount_cifs_root(void) 527*a6a41d39SChristoph Hellwig { 528*a6a41d39SChristoph Hellwig } 529*a6a41d39SChristoph Hellwig #endif /* CONFIG_CIFS_ROOT */ 5308902dd52SPaulo Alcantara (SUSE) 531f9259be6SChristoph Hellwig static bool __init fs_is_nodev(char *fstype) 532f9259be6SChristoph Hellwig { 533f9259be6SChristoph Hellwig struct file_system_type *fs = get_fs_type(fstype); 534f9259be6SChristoph Hellwig bool ret = false; 535f9259be6SChristoph Hellwig 536f9259be6SChristoph Hellwig if (fs) { 537f9259be6SChristoph Hellwig ret = !(fs->fs_flags & FS_REQUIRES_DEV); 538f9259be6SChristoph Hellwig put_filesystem(fs); 539f9259be6SChristoph Hellwig } 540f9259be6SChristoph Hellwig 541f9259be6SChristoph Hellwig return ret; 542f9259be6SChristoph Hellwig } 543f9259be6SChristoph Hellwig 544f9259be6SChristoph Hellwig static int __init mount_nodev_root(void) 545f9259be6SChristoph Hellwig { 546f9259be6SChristoph Hellwig char *fs_names, *fstype; 547f9259be6SChristoph Hellwig int err = -EINVAL; 5486e7c1770SChristoph Hellwig int num_fs, i; 549f9259be6SChristoph Hellwig 550f9259be6SChristoph Hellwig fs_names = (void *)__get_free_page(GFP_KERNEL); 551f9259be6SChristoph Hellwig if (!fs_names) 552f9259be6SChristoph Hellwig return -EINVAL; 553b51593c4SVivek Goyal num_fs = split_fs_names(fs_names, PAGE_SIZE, root_fs_names); 554f9259be6SChristoph Hellwig 5556e7c1770SChristoph Hellwig for (i = 0, fstype = fs_names; i < num_fs; 5566e7c1770SChristoph Hellwig i++, fstype += strlen(fstype) + 1) { 557b51593c4SVivek Goyal if (!*fstype) 558b51593c4SVivek Goyal continue; 559f9259be6SChristoph Hellwig if (!fs_is_nodev(fstype)) 560f9259be6SChristoph Hellwig continue; 561f9259be6SChristoph Hellwig err = do_mount_root(root_device_name, fstype, root_mountflags, 562f9259be6SChristoph Hellwig root_mount_data); 563f9259be6SChristoph Hellwig if (!err) 564f9259be6SChristoph Hellwig break; 565f9259be6SChristoph Hellwig } 566f9259be6SChristoph Hellwig 567f9259be6SChristoph Hellwig free_page((unsigned long)fs_names); 568f9259be6SChristoph Hellwig return err; 569f9259be6SChristoph Hellwig } 570f9259be6SChristoph Hellwig 5719361401eSDavid Howells #ifdef CONFIG_BLOCK 572*a6a41d39SChristoph Hellwig static void __init mount_block_root(void) 573c69e3c3aSVishnu Pratap Singh { 574c69e3c3aSVishnu Pratap Singh int err = create_dev("/dev/root", ROOT_DEV); 575c69e3c3aSVishnu Pratap Singh 576c69e3c3aSVishnu Pratap Singh if (err < 0) 577c69e3c3aSVishnu Pratap Singh pr_emerg("Failed to create /dev/root: %d\n", err); 578e3102722SChristoph Hellwig mount_root_generic("/dev/root", root_mountflags); 579c69e3c3aSVishnu Pratap Singh } 580*a6a41d39SChristoph Hellwig #else 581*a6a41d39SChristoph Hellwig static inline void mount_block_root(void) 582*a6a41d39SChristoph Hellwig { 583*a6a41d39SChristoph Hellwig } 584*a6a41d39SChristoph Hellwig #endif /* CONFIG_BLOCK */ 585*a6a41d39SChristoph Hellwig 586*a6a41d39SChristoph Hellwig void __init mount_root(void) 587*a6a41d39SChristoph Hellwig { 588*a6a41d39SChristoph Hellwig switch (ROOT_DEV) { 589*a6a41d39SChristoph Hellwig case Root_NFS: 590*a6a41d39SChristoph Hellwig mount_nfs_root(); 591*a6a41d39SChristoph Hellwig break; 592*a6a41d39SChristoph Hellwig case Root_CIFS: 593*a6a41d39SChristoph Hellwig mount_cifs_root(); 594*a6a41d39SChristoph Hellwig break; 595*a6a41d39SChristoph Hellwig case 0: 596*a6a41d39SChristoph Hellwig if (root_device_name && root_fs_names && mount_nodev_root() == 0) 597*a6a41d39SChristoph Hellwig break; 598*a6a41d39SChristoph Hellwig fallthrough; 599*a6a41d39SChristoph Hellwig default: 600*a6a41d39SChristoph Hellwig mount_block_root(); 601*a6a41d39SChristoph Hellwig break; 602*a6a41d39SChristoph Hellwig } 6031da177e4SLinus Torvalds } 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds /* 6061da177e4SLinus Torvalds * Prepare the namespace - decide what/where to mount, load ramdisks, etc. 6071da177e4SLinus Torvalds */ 6081da177e4SLinus Torvalds void __init prepare_namespace(void) 6091da177e4SLinus Torvalds { 6101da177e4SLinus Torvalds if (root_delay) { 6111da177e4SLinus Torvalds printk(KERN_INFO "Waiting %d sec before mounting root device...\n", 6121da177e4SLinus Torvalds root_delay); 6131da177e4SLinus Torvalds ssleep(root_delay); 6141da177e4SLinus Torvalds } 6151da177e4SLinus Torvalds 616216773a7SArjan van de Ven /* 617216773a7SArjan van de Ven * wait for the known devices to complete their probing 618216773a7SArjan van de Ven * 619216773a7SArjan van de Ven * Note: this is a potential source of long boot delays. 620216773a7SArjan van de Ven * For example, it is not atypical to wait 5 seconds here 621216773a7SArjan van de Ven * for the touchpad of a laptop to initialize. 622216773a7SArjan van de Ven */ 623216773a7SArjan van de Ven wait_for_device_probe(); 624d779249eSGreg Kroah-Hartman 6251da177e4SLinus Torvalds md_run_setup(); 6261da177e4SLinus Torvalds 6271da177e4SLinus Torvalds if (saved_root_name[0]) { 6281da177e4SLinus Torvalds root_device_name = saved_root_name; 6292d62f488SAdrian Hunter if (!strncmp(root_device_name, "mtd", 3) || 6302d62f488SAdrian Hunter !strncmp(root_device_name, "ubi", 3)) { 631e3102722SChristoph Hellwig mount_root_generic(root_device_name, root_mountflags); 632e9482b43SJoern Engel goto out; 633e9482b43SJoern Engel } 6341da177e4SLinus Torvalds ROOT_DEV = name_to_dev_t(root_device_name); 6351da177e4SLinus Torvalds if (strncmp(root_device_name, "/dev/", 5) == 0) 6361da177e4SLinus Torvalds root_device_name += 5; 6371da177e4SLinus Torvalds } 6381da177e4SLinus Torvalds 6391da177e4SLinus Torvalds if (initrd_load()) 6401da177e4SLinus Torvalds goto out; 6411da177e4SLinus Torvalds 642cc1ed754SPierre Ossman /* wait for any asynchronous scanning to complete */ 643cc1ed754SPierre Ossman if ((ROOT_DEV == 0) && root_wait) { 644cc1ed754SPierre Ossman printk(KERN_INFO "Waiting for root device %s...\n", 645cc1ed754SPierre Ossman saved_root_name); 646aa5f6ed8SChristoph Hellwig while (!driver_probe_done() || 647cc1ed754SPierre Ossman (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0) 64839a0e975SJungseung Lee msleep(5); 649216773a7SArjan van de Ven async_synchronize_full(); 650cc1ed754SPierre Ossman } 651cc1ed754SPierre Ossman 6521da177e4SLinus Torvalds mount_root(); 6531da177e4SLinus Torvalds out: 6545e787dbfSDominik Brodowski devtmpfs_mount(); 655c60166f0SChristoph Hellwig init_mount(".", "/", NULL, MS_MOVE, NULL); 6564b7ca501SChristoph Hellwig init_chroot("."); 6571da177e4SLinus Torvalds } 65857f150a5SRob Landley 6596e19ededSRob Landley static bool is_tmpfs; 660f3235626SDavid Howells static int rootfs_init_fs_context(struct fs_context *fc) 66157f150a5SRob Landley { 6626e19ededSRob Landley if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs) 663f3235626SDavid Howells return shmem_init_fs_context(fc); 6646e19ededSRob Landley 665f3235626SDavid Howells return ramfs_init_fs_context(fc); 66657f150a5SRob Landley } 66757f150a5SRob Landley 668fd3e007fSAl Viro struct file_system_type rootfs_fs_type = { 66957f150a5SRob Landley .name = "rootfs", 670f3235626SDavid Howells .init_fs_context = rootfs_init_fs_context, 67157f150a5SRob Landley .kill_sb = kill_litter_super, 67257f150a5SRob Landley }; 67357f150a5SRob Landley 674037f11b4SAl Viro void __init init_rootfs(void) 67557f150a5SRob Landley { 6766e19ededSRob Landley if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] && 677037f11b4SAl Viro (!root_fs_names || strstr(root_fs_names, "tmpfs"))) 6786e19ededSRob Landley is_tmpfs = true; 67957f150a5SRob Landley } 680